CH.31

Question 0

If a macromolecule has (a) _____, it will break down into smaller molecules.

a. main-chain scission
b. point lesion
c. cross-linking
d. point mutation

Answer 0

b. point lesion

Question 0

___ is the most radio sensitive molecule.

Answer 0

DNA

Question 1

Half as much DNA is present in __ and __.

Answer 1

G1 G2

Question 2

In vitro irradiation of macromolecules causes _____ damage to macromolecules.

a. repairable
b. reversible
c. irreversible
d. both A and B

Answer 2

d. both A and B

Question 2

At low doses, ____ are considered to be the cellular radiation damage that results in the stochastic radiation effects observed at the whole body level.

Answer 2

Point lesions

Question 3

The most radiosensitive macromolecule is _____.

a. protein
b. DNA
c. mRNA
d. tRNA

Answer 3

b. DNA

Question 3

Radiation induced molecular ______ increases the viscosity of a macromolecular solution.

Answer 3

Cross linking

Question 4

DNA is contained in the _____ of the cell nucleus.

a. proteins
b. cytoplasm
c. chromosomes
d. RNA

Answer 4

c. chromosomes

Question 4

_____ scission is reduces not only the size of the marcromolecule but also the viscosity of the solution.

Answer 4

Main chain

Question 5

A type of DNA damage that may not be reversible is a _____.

a. cross-linking
b. base change or loss
c. rung breakage
d. severed side rail

Answer 5

b. base change or loss

Question 5

A ___ results in the change or loss of a base, which creates an abnormal gene.

Answer 5

Point mutation

Question 6

Radiation damage to DNA can result in _____.

a. cell death
b. malignant disease
c. genetic changes
d. any of the above

Answer 6

d. any of the above

Question 6

The radio lysis of water results in the formation of ___and ____.

Answer 6

Ions and free radicals

Question 7

Molecular lesions of DNA are called _____.

a. point mutations
b. broken side rails
c. cross-linking
d. rung breaks

Answer 7

a. point mutations

Question 7

___ is an uncharged molecule that contains a single unpaired electron in the outer shell.

Answer 7

Free radical

Question 8

The principal radiation interaction within the human body is with _____.

a. DNA
b. macromolecules
c. water
d. RNA

Answer 8

c. water

Question 8

If the initial ionizing event occurs on the target molecule, the effects of radiation is _____.

Answer 8

Direct

Question 9

The disassociation of water molecules following irradiation is termed _____.

a. radiolysis
b. ionization
c. cross-linking
d. point mutation

Answer 9

c. cross-linking

Question 9

The principle effect of radiation on humans is ___.

Answer 9

Indirect

Question 10

When an atom of water is irradiated it first dissociates into _____.

a. two water atoms
b. an ion pair
c. free radicals
d. hydrogen peroxide

Answer 10

b. an ion pair

Question 10

What are the types of damage that can occur in DNA?

Answer 10

One side rail, both side rails, cross linking, rung breaking

Question 12

An indirect effect from ionizing radiation occurs on a _____ molecule.

a. target
b. DNA
c. water
d. free radical

Answer 12

c. water

Question 12

Ionizing events from irradiation are considered to be direct effects if they occur with _____ molecules.

a. water
b. DNA
c. protein
d. both A and B

Answer 12

b. DNA

Question 13

The principal radiation interactions within the human body are assumed to be _____.

a. indirect effects
b. direct effects
c. DNA damage
d. cell destruction

Answer 13

a. indirect effects

Question 14

Outside the body or outside the cell

Answer 14

in vitro

Question 15

Radiation-induced structural change in chromosomes.

Answer 15

cytogenetic damage

Question 16

c. Radiation damage that consists of a molecular lesion of the DNA and causes genetic mutation.

Answer 16

Point mutation

Question 17

d. A short-lived, highly reactive, uncharged molecule containing a single unpaired electron in the outermost shell.

Answer 17

free radical

Question 18

e. The radiobiologic theory that says for a cell to die, after radiation exposure, its target molecule must be inactivated.

Answer 18

Target theory

Question 19

The viscosity of a solution determines the degree of main chain scissions

Answer 19

Viscosity

Question 20

Some macromolecules have side structures that behave as though they have a sticky substance on their ends, and they attach to another macromolecule or to another segment of the same molecule.

Answer 20

Crosslinking

Question 21

* Two OH* free radicals can join to form _____ molecules. a. organic free radical b. hydroperoxyl c. hydrogen peroxide d. DNA

Answer 21

c. hydrogen peroxide

Question 22

h. Occurs when a radiation interaction occurs with the target

Answer 22

Radiation hit

Question 23

* Free radicals can be damaging because they are _____. a. unstable b. highly reactive c. radioactive d. both A and B

Answer 23

d. both A and B

Question 24

the process that creates energy for a cell by breaking down molecular nutrients that are brought to and diffused through the cell membrane

Answer 24

Catabolism

Question 25

the probability or frequency of the biologic response to radiation as a function of radiation dose. Disease incidence increases proportionally with dose, and there is no dose threshold.

Answer 25

Stochastic effect

Question 26

What is the difference b/w catabolism and anabolism?

Answer 26

4. Catabolism is the breakup of large molecules into smaller molecules. Anabolism is the construction of large molecules from smaller molecules

Question 28

Name the 3 principle observable effects of DNA irradiation.

Answer 28

cell death, genetic damage, and malignant disease

Question 29

What is the difference b/w direct effect and indirect effect?

Answer 29

18. A direct effect exists when the ionizing radiation interacts directly with the target molecule DNA. An indirect effect occurs when the interaction is with some other molecule, resulting in the formation of free radicals, which then transfer this excess energy to the DNA.

Question 38

*In what phase of the cell cycle does the DNA ladder open up in the middle of each rung and consist of only a single chain?

Answer 38

5. Synthesis (S) phase